A 168-mile-long channel near Mars' Ascraeus Mons volcano wasn't created by water as scientists have previously thought. New high-resolution images suggest that this trench was created by molten lava. What does this mean for the search for water on Mars?

We started seeing that, instead of this [liquid] cutting into an existing surface, it was building a surface-it built a ridge up to 40 meters [...] You see it all the time in volcanic settings. So that's kind of our smoking gun.

This doesn't mean that water-formed valleys don't exist on Mars, but it does mean that researchers will have to account for volcanism more when analyzing images of Martian topography. Want NASA to take a peek at a certain area of Mars? Submit your request to HiWish, a site where you can suggest which Martian landscapes NASA should photograph next.